Gearbox Software has confirmed the rumoured development of Borderlands 3 via the release of an official development trailer, while surprising fans of the series with the announcement of a free upgrade for the original game.

During a presentation at the Penny Arcade Expo (PAX) late last night, Gearbox confirmed the rumours are true. A development trailer reveals that the game will feature multiple planets, four new Vault Hunter characters, and the art style and humour - and vast quantity of procedurally-generated weapons - for which the series is known.

At the same time, Gearbox announced that it was revamping the original Borderlands with a new Game of the Year edition. Due to land in the middle of next week, the re-release will see the addition of a mini-map similar to the one in Borderlands 2, automatic collection of some types of loot as the player passes over them, a simplified inventory system, additional hand-crafted 'legendary' weapons, and visual improvements. There are also gameplay changes, the company has confirmed, teasing a harder final boss.

No release date has been provided for Borderlands 3, but Borderlands Game of the Year Edition will be available on April 3rd as a standalone title and as a free upgrade for those who already own the original Borderlands - and it brings with it the expansion, too.